/**
* Executes query and returns a single row of result.
* @param Connection $db the DB connection used to create the DB command.
* If null, the DB connection returned by [[modelClass]] will be used.
* @return ActiveRecord|array|null a single row of query result. Depending on the setting of [[asArray]],
* the query result may be either an array or an ActiveRecord object. Null will be returned
* if the query results in nothing.
*/
public function one($db = null)
{
$row = parent::one($db);
if ($row !== false) {
$models = $this->populate([$row]);
return reset($models) ?: null;
} else {
return null;
}
}
/**
* Session read handler.
* Do not call this method directly.
* @param string $id session ID
* @return string the session data
*/
public function readSession($id)
{
$query = new Query();
$query->from($this->sessionTable)->where('[[expire]]>:expire AND [[id]]=:id', [':expire' => time(), ':id' => $id]);
if (isset($this->readCallback)) {
$fields = $query->one($this->db);
return $fields === false ? '' : $this->extractData($fields);
}
$data = $query->select(['data'])->scalar($this->db);
return $data === false ? '' : $data;
}